Markitect schema-validation integration use case and fixture for Markdown proxy documents

workplans/KONT-WP-0005-asset-registry-governance-state.md

@@ -45,6 +45,12 @@ adapter metadata on representations or versions. It must not make Markitect
 document classes canonical engine entities, and asset identity must remain
 independent of Markitect snapshot identity.
 
+Markdown proxy documents are valid source, normalized, or derived
+representations for assets when Markitect selectors, contracts, document
+schemas, or workflows are useful. They remain adapter representations under
+engine governance; the registry still owns identity, metadata, lifecycle,
+policy, lineage, and audit.
+
 ## Implementation Note
 
 The first registry slice is recorded in
@@ -59,11 +65,11 @@ As of 2026-05-06, the registry core has a working asset service, in-memory and
 SQLite repositories, policy gateway boundary, audit events, versions,
 representations, metadata records, context entities, asset/context
 relationships, idempotent asset creation, and custom metadata schema
-validation before registry writes. Remaining work in this workplan is
-concentrated on schema registry/policy assignment, standard metadata filtering
-beyond lifecycle and asset type, restore/supersession operations, conflict
-semantics beyond sequence/idempotency checks, and batch partial-failure
-envelopes.
+validation before registry writes. It now also includes a durable metadata
+schema registry and assignment rules for policy-selected validation. Remaining
+work in this workplan is concentrated on standard metadata filtering beyond
+lifecycle and asset type, restore/supersession operations, conflict semantics
+beyond sequence/idempotency checks, and batch partial-failure envelopes.
 
 ## G5.1 - Implement stable asset identity and source references